The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Food sensitivity, especially as it relates to irritable bowel syndrome (IBS), often presents with chronic abdominal pain, discomfort, bloating, and/or change in bowel habits and is not well understood in the medical community. Most typically, IBS is diagnosed by elimination of other pathological conditions (e.g., bacterial or protozoan infection, lactose intolerance, etc.) that may have similar or overlapping symptoms. However, IBS is often quite diverse with respect to dietary items triggering symptoms, and no standardized test to help identify trigger food items with a reasonable degree of certainty is known, leaving such patients often to trial-and-error.
While there are some commercially available tests and labs to help identify trigger foods, the quality of the test results from these labs is generally poor as is reported by a consumer advocacy group (e.g., http://www.which.co.uk/news/2008/08/food-allergy-tests-could-risk-your-health-154711/). Most notably, problems associated with these tests and labs were high false positive rates, high false negative rates, high intra-patient variability, and inter-laboratory variability, rendering such tests nearly useless. Similarly, further inconclusive and highly variable test results were also reported elsewhere (Alternative Medicine Review, Vol. 9, No. 2, 2004: pp 198-207), and the authors concluded that this may be due to food reactions and food sensitivities occurring via a number of different mechanisms. For example, not all IBS patients show positive response to food A, and not all IBS patients show negative response to food B. Thus, even if an IBS patient shows positive response to food A, removal of food A from the patient's diet may not relieve the patient's IBS symptoms. In other words, it is not well determined whether food samples used in the currently available tests are properly selected based on the high probabilities to correlate sensitivities to those food samples to IBS.
Many have made efforts to select food items or allergens to include in the test panel for immunoassay tests. For example, US Patent Application No. 2007/0122840 to Cousins discloses selection of 29 food allergens that are included in the test panel for ELISA assay. The 29 food allergens are selected based on the frequency of IgG positivity in preliminary experiments with a larger panel of food allergens. However, Cousins fails to teach any quantitative and/or statistical analysis for the selected antigens and as such fails to provide any rationale for the selection. Indeed, Cousin's method to select 29 food allergens for test panel has been criticized that the selection is rather arbitrary. For example, Croft criticized in a paper titled “IgG food antibodies and irritating the bowel”, published in Gastroenterology, Vol. 128, Issue 4, p. 1135-1136, that Cousin's method is not clear whether the quantity and range of food antibodies being measured are similar or completely different to non-IBS patients or non-food intolerant patients because it lacks controls (normal or non-IBS control subject). Thus, it is at best unclear if Cousins achieves any improvement with respect to false positive and false negative results.
For another example, US Patent Application No. 2011/0306898 to Stierstorfer discloses selection of 41 food substances as test materials on skin patches. The 41 food substances are selected based on chemical compounds included in the food substances (e.g., vanillin, cinnamic aldehyde, sorbic acid, etc.). The food substances are tested on IBS patients or IBS-suspected patients for allergic contact dermatitis. However, Stierstorfer also fails to disclose how the false positive or false negative food allergens are eliminated and whether the food allergens are selected based on the gender stratification among IgG positivity results.
All publications identified herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Thus, even though various tests for food sensitivities are known in the art, all or almost all of them suffer from one or more disadvantages. Therefore, there is still a need for improved compositions, devices, and methods of food sensitivity testing, especially for identification and possible elimination of trigger foods for patients identified with or suspected of having IBS.